A new study led by Feinberg professors revealed that pregnant people’s emotional experiences can have developmental effects on their babies.

The researchers published their findings earlier this month in the journal Infancy, reporting on their findings that more volatile stress levels in pregnant people led to more fear and distress in their three-month-old children. 

Feinberg Prof. and lead study author Leigha MacNeill said the paper was part of a growing field of research.

“We still don’t have a great idea of how the prenatal environment affects child development,” she said. “In psychology, it’s still emerging.”

MacNeill said she originally thought about the study in relation to the pandemic. Stress increased for everyone across the board, but she was particularly interested in how COVID-19 affected stress levels for pregnant people. 

The study tracked individuals’ stress levels by groups, one tracked before the pandemic in 2019 and one afterward, up to four times a day for 14 weeks. The substantial amount of  contact with participants was unique, according to Feinberg Prof. and study co-author Renee Edwards. 

“The idea of being able to do repeated measures to really look at — in real time and on a much more micro level — how stress and mental health symptoms and other things change is a new way of looking at stress,” Edwards said.

The study didn’t find heightened stress levels on average in pregnant people during the pandemic, which both MacNeill and Edwards said surprised them. However, they also said the sample population, which was disproportionately educated and affluent, may have been shielded from the worst effects of the pandemic. 

But the study did conclude that high stress levels aren’t the sole reason for the negative effects in children, MacNeill said. Rather, chaotic swings in stress are damaging to the child’s development.

“These fluctuations, someone who goes through those extremes more often, that is what mattered for infants’ temperamental, negative emotions rather than having a consistent level of stress,” MacNeill said.

While the study establishes a relationship between experiences during pregnancy and childhood development, it doesn’t explain why that link exists.

That question is what future research should focus on, Feinberg Prof. and study co-author Yudong Zhang said.

“We know that this relationship is not causation,” Zhang said. “A deeper dive into the specific mechanisms, either moderators or mediators in between this process, in the future would probably be a related or add-on study.”

MacNeill said she also wants to learn more about the biological causes of the relationship, saying it could also provide a better overall understanding of it during pregnancy. 

Edwards said another priority should be using the study’s data to develop supportive interventions for families to avoid the negative developmental effects.

“How then do we translate this into practice?” Edwards said. “Make interventions more targeted and responsive to be as effective as they can be.”

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Twitter: @GiangiulioDavis

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